Icon of application to panel

I use fvwm 2.6.7 with default config. When I open pdf file, in panel appears small icon (white paper with text)
with name of file just right of icon. I’d like to use icon of pdf adobe instead of present icon. How can I do this?
The same question for other sort of files - tex, odt, mathematica … Can I control this by myself or it is connected
with mime type of file? In the same time when I open DeadBeef or Double Commander in the panel appear icons
of these programs.

Look up the MiniIcon style in the man page. You may need EWMHMiniIconOverride as well. This is all documented in the man pages.

Thank you for direction. Man page is very detailed but very huge. It will be better to put on the top om man
page additional document like brief review with short description of operators. Fvwm is very good wm but
everybody needs to read at the beginning a lot of pages. Good way is modifying default config, which I really use.